Counterbalanced advancing metal cutting saw

ABSTRACT

An advancing power saw used for any metal cutting application. The power saw is provided with an oscillating mechanism that drives the saw up and down in a vertical direction. A hydraulic cylinder advances the saw toward the metal being cut while the saw is oscillating creating a circular pathway for the saw blade during the cutting operation. A balancing apparatus is provided in association with the saw blade that advances in an opposite direction to that of the saw blade to act as a counterbalance for the saw. The balancing apparatus has a weight provided at one end which dampens the vibrations created by the saw during the cutting operation and substantially equalizes pressure on the saw blade.

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] The present invention relates to power saws used for any metalcutting application. More particularly, the field of the inventioninvolves such power saws used for cutting metal objects such as railroadrails used in railroad joints.

[0003] 2. Description of the Related Art

[0004] In general, metal objects such as railroad rails, engine blocks,and stainless steel rods are cut for several purposes including formingrailroad joints and material testing. These types of metals areconventionally cut by power saws. Conventional power saws include a sawblade that is driven by a belt coupled to a relatively high horsepowermotor. The saw blade is advanced downwardly at a constant rate towardthe piece of metal by a hydraulic cylinder or the like. Another featureof conventional power saws used to cut metal is an oscillating devicewhich provides the saw blade with an oscillatory motion as it advancesthrough the metal object. The saw blade follows a circular path as itcuts through the metal.

[0005] Power saws lacking an oscillating device maintain the blade inconstant contact with the metal being cut. The temperature of the metalarticle at the point of contact thus elevates becoming too hot andalters the integrity of the metal. Further, due to the hightemperatures, the saw blade tends to cut towards the hotter areas of themetal as it is being forced through the object. The resulting cutsurface of the metal then has ridges and is not substantially flat whichprevent uniform contact of the cut surfaces of two adjacent railroadrails in a railroad joint for example. The life of the saw blade isreduced in this type of power saw because of the stress applied to theblade from the force of the blade in constant contact with the metalbeing cut. Power saws having oscillating devices dissipate the heatcreated by the cutting operation so that the integrity of the metal doesnot change. However, the oscillatory motion of the saw blade is notcontrolled in a smooth, continuous motion which prevents dissipation ofthe heat created during cutting, thereby allowing the integrity of themetal to change. Once this occurs, the horsepower requirements necessaryto force the saw through the remainder of the piece of metal being cutas well as the stress applied to the saw blade increase drastically.

[0006] Conventional power saws for cutting metal objects lack control ofthe vibrations created during the cutting operation. Such conventionalsaws lack speed desired for the cutting operation. Further, conventionalpower saws require frequent replacement of the saw blade.

SUMMARY OF THE INVENTION

[0007] The present invention involves a counterbalanced, oscillatingadvancing power saw capable of cutting several types of metal. The powersaw includes an oscillating motor which oscillates the saw bladevertically. The saw also includes a hydraulic cylinder which forces thesaw blade toward the piece of metal being cut. A counterbalance isarranged to move in the opposite direction of the saw as its bladeadvances towards the metal to facilitate an approximately constantcutting pressure as the saw blade advances. The saw also includes arotating platform which allows the cut through the metal to be at anydesirable angle up to 45 degrees left or right from center.

[0008] The present invention provides an advancing power saw for cuttingmetal objects. The power saw has a platform and a saw support platewhich is disposed on the platform. A saw blade assembly is disposed uponthe support plate and includes a saw blade coupled with a motor andassociated with an oscillating mechanism. A counterweight is operativelyassociated with the support plate and arranged to move in a directionopposite to the direction the support plate moves.

[0009] In an exemplary embodiment, the power saw includes an advancingmechanism for advancing and retracting the support plate. A pulleysystem is coupled to the counterweight and the support plate such thatthe pulley system advances the counterweight in an equal and oppositedirection of the support plate. The counterweight is made of a pluralityof rails where at least one of the plurality of rails is operativelyconnected to the support plate, and at least one of the plurality ofrails is operatively connected to the counterweight, such that the railsactuate in opposite directions. The counterweight has sufficient mass inrelation to the power saw to dampen vibrations in the power saw andequalize the pressure on the saw blade. The power saw further includesat least one hydraulic cylinder is associated with the rails tofacilitate the cutting stroke and return stroke of the saw assembly. Forlateral movement of the saw assembly, at least one hydraulic cylinder isassociated with the counterweight and at least one hydraulic cylinder isassociated with the support plate. The oscillating mechanism includes anoscillating motor with is associated with the oscillating mechanism by aconnecting arm. The support plate and the counterweight are supported byat least one pivot support disposed atop the platform. The pivot supportis disposed beneath the rails. The pivot support extends above therails.

[0010] In another form, the present invention provides an advancingpower saw for cutting metal objects including a platform having amovable support plate. Further included is an oscillating saw operationfor cutting the metal objects disposed on the support plate and abalancing operation for dampening vibration of the oscillating sawoperation.

[0011] In an exemplary embodiment, the oscillating saw operationincludes a saw blade rotatably supported atop the support plate. Atleast one pivot support is provided to support the support plate abovethe platform. The pivot support is disposed beneath the rails. The pivotsupport extends above the rails. The oscillating saw operation isoperatively associated with an oscillating motor by a connecting arm. Anadvancing mechanism is provided and is operatively associated with thesupport plate such that the advancing mechanism advances and retractsthe saw blade. The balancing operation is operatively associated withthe support plate and arranged to move in a direction opposite to thedirection the support plate moves. The balancing operation includes aplurality of rails, at least one of which is operatively connected tothe support plate, and at least one of which is operatively connected tothe balancing operation. The power saw further includes at least onehydraulic cylinder which is associated with the rails. At least onehydraulic cylinder is associated with the balancing operation and atleast one hydraulic cylinder is associated with the support plate. Thebalancing operation supports at one end a counterbalance which dampensvibrations in the power saw and is a weight. The counterbalance furtherequalizes pressure on the saw blade. Further included in the oscillatingsaw operation is a pulley assembly coupled to the balancing operationand to the support plate to advance the balancing operation in adirection opposite of the support plate.

[0012] An advantage of the power saw of the present invention is that byoscillating the saw blade, the contact point between the blade and themetal is not constant to create high temperatures, eliminating thepossibility of altering the integrity of the metal. Another advantage ofthe power saw is the balancing apparatus which counterbalances theweight of the saw blade to control vibrations produced during thecutting operation and substantially equalizes pressures on the sawblade. This lengthens the life of the saw blade and allows the metal tobe cut faster.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above mentioned and other features and objects of thisinvention, and the manner of attaining them, will become more apparentand the invention itself will be better understood by reference to thefollowing description of embodiments of the invention taken inconjunction with the accompanying drawings, wherein:

[0014]FIG. 1 is a perspective view of the power saw of the presentinvention;

[0015]FIG. 2 is a side elevation of the power saw of FIG. 1;

[0016]FIG. 3 is an enlarged, sectional view showing the oscillatingmechanism of the present invention in the initial position;

[0017]FIG. 4 is the oscillating mechanism of FIG. 3 in an actuatedposition;

[0018]FIG. 5 is an enlarged, fragmentary view of the oscillatingmechanism of FIG. 3 taken along view lines 5-5 of FIG. 3 showing thecontact point with the saw support plate;

[0019]FIG. 6 is a fragmentary, perspective view of the balancingapparatus of the present invention in the advanced position;

[0020]FIG. 7 is a side, sectional view of the pulley system of thepresent invention which advances the balancing apparatus;

[0021]FIG. 8 is a rear, sectional view of the present invention takenalong view line 8-8 of FIG. 7;

[0022]FIG. 9 is a rear, sectional view of the present invention takenalong view line 9-9 of FIG. 7;

[0023]FIG. 10 is a rear, sectional view of the present invention takenalong view line 10-10 of FIG. 7;

[0024]FIG. 11 is a side elevational view of the power saw of the presentinvention in its initial position;

[0025]FIG. 12 is the power saw of FIG. 11 with the saw blade andbalancing apparatus partially advanced;

[0026]FIG. 13 is the power saw of FIG. 11 with the saw blade andbalancing apparatus completely advanced;

[0027]FIG. 14 is a plan view of the power saw of the present inventionprovided with coolant jets;

[0028]FIG. 15 is a side elevation of a second embodiment of the powersaw of the present invention;

[0029]FIG. 16 is a sectional view of the pulley system and balancingapparatus taken along view line 16-16 of FIG. 15;

[0030]FIG. 17 is a sectional view of the pulley system and balancingapparatus taken along view line 17-17 of FIG. 15;

[0031]FIG. 18 is a rear, sectional view of the second embodiment of thepresent invention taken along view line 18-18 of FIG. 15;

[0032]FIG. 19 is a rear, sectional view of the second embodiment of thepresent invention taken along view line 19-19 of FIG. 15; and

[0033]FIG. 20 is a rear, sectional view of the second embodiment of thepresent invention taken along view line 20-20 of FIG. 15.

[0034] Corresponding reference characters indicate corresponding partsthroughout the several views. Although the drawings representembodiments of the present invention, the drawings are not necessarilyto scale and certain features may be exaggerated in order to betterillustrate and explain the present invention. The exemplification setout herein illustrates embodiments of the invention, in several forms,and such exemplifications are not to be construed as limiting the scopeof the invention in any manner.

DESCRIPTION OF THE PRESENT INVENTION

[0035] The embodiments disclosed below are not intended to be exhaustiveor limit the invention to the precise form disclosed in the followingdetailed description. Rather, the embodiments are chosen and describedso that others skilled in the art may utilize their teachings.

[0036] Referring to FIGS. 1 and 2, advancing power saw 10 is used forcutting a plurality of types of metal including cast iron engine blocks,stainless steel rods and railroad rail 20. Railroad rail 20 isillustrated in the figures and discussed below as an example of the typeof metal that can be cut by power saw 10. Power saw 10 is supported bybase 12 upon which rotatable platform 14 is mounted. Base 12 andplatform 14 are both constructed from a material such as steelpossessing strength properties to support the weight of power saw 10. Asshown in FIG. 2, between base 12 and 14 are fixed disk 16 and movabledisk 18 also constructed from a material such as steel and stacked atopone another. Fixed disk 16 is secured to base 12 and movable disk 18 isattached to platform 14 by any suitable means such as welding or the useof fasteners. Movable disk 18 is rotatably mounted with respect to fixeddisk 16 so as to permit rotation of platform 14 and thus power saw 10,allowing rail 20 to be cut at any desired angle. Optionally, a powerpositioning device, e.g. a hydraulic or electric motor, may drive therotation of platform 14. Thus, such a saw assembly could be accessiblefrom any direction, allowing for the saw assembly to be used on morethan one production line. Base 12 is fixed to the floor in the areawhere power saw 10 is being used by fasteners 22 such as bolts orscrews.

[0037] Advancing power saw 10 includes saw support plate 24 mounted atopand movable in relation to balancing apparatus 26 as illustrated inFIGS. 1, 2, 11, 12, and 13. Saw support plate 24 and balancing apparatus26 are held above platform 14 by a pair of pivot supports 28,oscillating mechanism 30 and a pair of springs 32. Pivot supports 28 aresecured to the top surface of platform 14 by suitable methods such aswelding or brazing and are disposed on both sides of end 34 of platform14 to support the width of saw support plate 24 and balancing apparatus26. At end 36 of platform 14 is oscillating mechanism 30 which supportssaw support plate 24 and balancing apparatus 26 and causes the up anddown movement of power saw 10 in the direction of arrow 42. Pivotsupports 28 have apertures 38 in which the ends of beam 40 arejournalled for rotation. As oscillation mechanism 30 moves power saw 10up and down in the direction of arrow 42, beam 40 supporting balancingapparatus 26 (FIGS. 1, 2, 6 and 7) acts as a pivots about which sawsupport plate 24 and balancing apparatus 26 rotate. Oscillatingmechanism 30 will be discussed in greater detail below. Also supportingplate 24 and balancing apparatus 26 are a pair of springs 32 disposed onthe top surface of platform 14 between pivot supports 28 and oscillatingmechanism 30. Springs 32 help facilitate and maintain the oscillatorymotion of power saw 10 created by oscillating mechanism 30. Springs 32could also be a device such as a hydraulic cylinder.

[0038] Referring to FIGS. 3, 4 and 5, oscillating mechanism 30 alongwith balancing apparatus 26 prevent saw blade 46 from being in contactwith metal articles such as rail 20 for substantial lengths of timewhich would create high temperatures causing the integrity of rail 20 tochange. Secured to platform 14 by fasteners 52, oscillating motor 50 isoperatively associated with oscillating mechanism 30 by connecting arm54. Oscillating motor 50 is a motor of an appropriate size for actuatingconnecting arm 54 back and forth in the direction of arrow 62 andoscillating power saw 10. Motor 50 includes motor output 56 which isfixed by any suitable method such as welding or fasteners withinaperture 58 located in plate 60. As motor output 56 rotates in thedirection of arrow 62 plate 60 rotates as shown in FIGS. 3 and 4.Extending substantially perpendicularly from plate 60 is peg 64 whichmay be integrally formed with plate 60 or secured within a secondaperture located in plate 60. The opposite end of peg 64 is received inaperture 66 located in end 68 of connecting arm 54. End 70 of connectingarm 54 is provided with eyebolt 72 which is threadedly secured to arm54. Eyebolt 72 has hole 74 through its center which receives bolt 76 tofasten connecting arm 54 to plate 78 of oscillating mechanism 30.Oscillating motor 50 pivots plate 60 in the direction of arrow 62 whichactuates connecting arm 54 and thus plate 78 back and forth in thedirection of arrow 80. The operation of oscillating motor 50 may bevariably controlled depending on the size and shape of the materialbeing cut. This motion of plate 78 generates the oscillations of powersaw 10 as will be described below.

[0039] Referring to FIG. 5, the opposite end of plate 78 from the linkwith connecting arm 54 is fixedly mounted on shaft 82. The ends of shaft82 are pivotally mounted within pillow blocks 84 which are secured toplatform 14 by fasteners 86. A square collar 88 is disposed on shaft 82between pillow blocks 84. Elongated plate 90 is attached to surface 92of collar 88 by means such as welding or brazing. Collar 88 and plate 90are configured with respect to shaft 82 in such a manner that whenoscillating mechanism 30 is in its initial position shown in FIGS. 3 and5, plate 90 stands approximately perpendicularly to platform 14. At eachend of plate 90 are members 94 which are secured to plate 90 by a pairof fasteners 96. Members 94 extend downwardly at an angle from plate 90so as to be positioned outside of and substantially below pillow blocks98. Pillow blocks 98 are secured by fasteners 100 to balancing apparatusend plate 102 extending downwardly and substantially perpendicular toend 104 of balancing apparatus 26. Balancing apparatus end plate 102 issecured to balancing apparatus 26 by fasteners 106. Each member 94 hasone end of shaft 108 fixed within aperture 110. Shaft 108 is positionedto contact pillow blocks 98 at 112 such that as connecting arm 54 ismoved away from pillow block 98 (FIG. 4), toward pivot supports 28, byoscillating motor 50, power saw 10 is forced upwardly in a direction ofarrow 42 (FIG. 2). As motor 50 continues to rotate output shaft 56,plate 60 moves back and forth in the direction of arrow 62 and plate 78in the direction of arrow 80 causing saw blade 46 to move continuouslyup and down in the direction of arrow 42. The distance in which sawblade 46 moves in the direction of arrow 42 is directly related to thelength of connecting arm 54 including eyebolt 72 which can be adjustedby threading eyebolt 72 further onto or off of connecting arm 54. Thecomponents of oscillating mechanism 30 and connecting arm 54 areconstructed from a material such as steel which is strong enough tosupport the weight of power saw 10 as it is oscillated.

[0040] Supported by pivot supports 28, oscillating mechanism 30, andsprings 32, saw support plate 24 is fixedly mounted atop balancingapparatus 26 and supports drive motor 44 which is operatively connectedto saw blade 46 through drive belt 48. Drive belt 48 is shown in FIGS. 1and 2 as a single belt but may consist of a plurality of belts. As shownin FIG. 1, saw blade 46 is fixedly mounted between ends 114 and 116 ofshaft 118. End 114 of shaft 118 is rotatably mounted in pillow block 120which is aligned with edge 128 of supporting plate 24. End 116 of shaft118 is rotatably mounted in pillow block 122 which is aligned with edge124 of cutout 126. Cutout 126 is located along the front edge of sawsupport plate 24 to provide clearance for saw blade 46. A third pillowblock 130 is aligned adjacent with edge 132 of cutout 126 so that shaft118 is rotatably supported on both sides of saw blade 46, reducing theamount of stress on shaft 118 created during the cutting operation. End116 passes through pillow block 130 and through aperture 134 in sawblade 46 to be received by pillow block 122. End 114 of shaft 118extends through pillow block 120 past edge 128 of plate 24 and has gear136 fixedly attached to end 114 by suitable methods such as welding orthe like. Alternatively, shaft 118 may be similarly mounted to bottomsurface 137 of saw support plate 24 if the application requires that sawblade 46 be mounted in a lower position.

[0041] Secured to the opposite end of saw support plate 24 from sawblade 46 is drive motor 44 fixed in position by fasteners 138 such asbolts or screws. Drive motor 44 is a 125 h.p. motor having output shaft140 which extends past edge 128 of plate 24 and has gear 142 fixedlymounted to shaft 140. It is noted that motor 44 may be of any sizesuitable to rotate saw blade 46 at the speeds required to cut rail 20.Gear 142 aligns with gear 136, both of which being engaged by drive belt48. As drive motor 44 rotates, output shaft 140 drives belt 48 whichcauses rotation of gear 142 and shaft 118. The rotation of shaft 118 istransferred to saw blade 46 to cut rail 20. Guard 144 standssubstantially perpendicularly from saw support plate 24 and is providedto protect motor 44 from sparks or debris created during the cutting ofrail 20.

[0042] Referring to FIGS. 6, 8, 9, and 10, balancing apparatus 26 willnow be discussed in greater detail. Balancing apparatus 26 maintainscontinuous oscillations of power saw 10 and controls vibrations producedduring the cutting operation. Balancing apparatus 26 further facilitatesa substantially constant cutting pressure against rail 20 as saw 10advances, thereby equalizing pressure on saw blade 46. By equalizingpressure on blade 46 and reducing the amount of vibrations passingthrough saw blade 46, the life of blade 46 is extended and the cutthrough rail 20 is faster. In order to control the vibrations createdduring operation of saw 10, balancing apparatus 26 is provided withcounterbalance or weight 146 at end 148. The amount of vibrationsproduced during the cutting operation varies, depending on the thicknessand type of material such as steel or stainless steel of rail 20.Counterbalance 146 may be in the range of 400 to 1500 lbs. depending onthe magnitude of the vibrations. The more severe the vibrations the moreweight is required to control them.

[0043] As shown in FIGS. 6, 8, 9 and 10, counterbalance 146 is supportedat end 148 by two outer, U-shaped beams or rails 150 and 152 which arewelded together at 154 and extend the length of balancing apparatus 26.Saw support plate 24 is secured to spacer plates 156 which simply raisesupport plate 24 over the upper surface of beams 152 so that as sawsupport plate 24 is advanced in one direction, it does not bind withbalancing apparatus 26 moving in the opposite direction. Spacer plates156 are welded to upper surface 158 of substantially L-shaped rails 160.Leg 162 of rails 160 extends downwardly from and is approximatelyperpendicular to leg 164 of rails 160. A pair of stationary I-beams orrails 166 are supported at one end by beam 40 and are secured tobalancing apparatus end plate 102 by fasteners 106 at the opposite end.Legs 162 along with I-beams 166 create cavities 168 in which rollers 170are disposed. Rollers 170 are fixed to leg 162 of rails 160 by fasteners172 and are in rolling contact with inner surfaces 180 of I-beams 166.Rollers 170 facilitate movement of saw support plate 24 and thus sawblade 46 in the direction of arrow 80 toward rail 20 (FIGS. 6, 12 and13) and back to the initial position of FIG. 11 after the cuttingoperation is complete. The opposite side of I-beam rails 166 formcavities 174 with U-shaped beams 150. Rollers 176 are disposed withincavities 174 and are rotatably mounted to beams 150 by fasteners 178.Rollers 176 are in rolling contact with inner surfaces 182 of I-beams166 for facilitating movement of counterbalance 146 in a directionopposite that of saw blade 46 during operation and back to the initialposition of FIG. 11 when rail 20 is completely cut.

[0044] Referring to FIGS. 6, 7, 11, 12 and 13, hydraulic cylinder 184,well known in the art, is provided to facilitate the cutting stroke andthe return stroke of saw blade 46 in both directions of arrow 80.Hydraulic cylinder 184 is supported by beam 40 at one end and includesrod 186. The end of rod 186 is secured to plate 188 downwardly extendingfrom saw support plate 24 by connector 190. Hydraulic fluid entershydraulic cylinder 184 through fluid lines 192 (FIG. 6), forcing rod 186out of cylinder 184. As rod 186 is forced out of cylinder 184, sawsupport plate 24 is advanced toward rail 20 (FIG. 12) to the actuatedposition of FIG. 13. Hydraulic fluid is released from cylinder 184 toallow rod 186 to retract, returning saw support plate 24 to the initialposition of FIG. 11.

[0045] Referring to FIG. 7, pulley assembly 194 advances balancingapparatus 26 in a direction opposite that of saw blade 46 during thecutting operation and retracts balancing apparatus 26 back to theinitial position (FIG. 11) once the cutting operation is complete. Crossmember 196 is welded to lower surface 198 of I-beams 166 (FIG. 8). Shaft200 is fixed at each end to a pair of downwardly extending supports 202.At the center of shaft 200 is gear 204 which is engaged by chain 206. Asshown in FIG. 7, near end 104 of balancing apparatus 26, chain 206 isalso engaged on gear 208 fixed to shaft 210 supported by downwardlyextending supports 212, similar to supports 202. Supports 212 aresecured to cross member 214 which is welded to surface 198 of theopposite end of stationary I-beams 166. Fixedly attached to chain 206are joints 216 and 218 which actuate chain 206 about gears 204, 208 andbalancing apparatus 26 as hydraulic cylinder 184 moves saw support plate24. Referring to FIG. 9, joint 216 includes extensions 220 which arewelded to lower surface 222 of beams 150. Each extension 220 is thenwelded to cross member 224 to join beams 150 together so that whenactuated, beams 150 advance and retract in unison. Extending downwardlyfrom the center of cross member 224 is the support 226 for collar 228which is fixed to chain 206 at this point. Similarly, joint 218 shown inFIG. 10 includes extensions 230 which are secured to surface 232 locatedon the underside of rails 160. Welded to the lower end of extensions 230is cross member 234 which joins rails 160 such that they advance andretract in unison. Collar 236 is welded directly to cross member 234 andis fixed to chain 206. In the initial position shown in FIG. 11, joints216 and 218 are closest together. As hydraulic cylinder 184 forces sawsupport plate 24 towards rail 20, joint 218 is moved toward support 212.The upper portion of chain 206 travels around gear 208 to force joint216 closer to supports 202. This movement of joint 216 forcescounterbalance 146 to move in a direction opposite that of saw supportplate 24. The movement of counterbalance 146 is proportional to sawsupport plate 24 as shown in FIGS. 12 and 13 such that the vibrationsproduced during the cutting operation are dampened by the weight ofcounterbalance 146. The dual motion of power saw 10 in the direction ofarrows 42 and 80 creates an elliptical pathway that saw blade 46 followsenabling the limited contact time between saw blade 46 and rail 20.

[0046] A second embodiment of balancing apparatus 26, pivots 28, andpulley assembly 194 of the present invention is illustrated in FIGS. 15through 20. Balancing apparatus 244 is similar to balancing apparatus 26in that stationary rail 246 along with rail 248 supporting saw supportplate 24 create cavity 250 for rollers 252. Stationary rail 246 and rail254 which supports counterbalance 146 define cavity 256 in which rollers258 are disposed. Rollers 252 and 258 then facilitate movement of sawsupport plate 24 in a direction towards rail 20 as counterbalance 146moves simultaneously in the opposite direction.

[0047] In this embodiment, rails 248 are advanced by concurrentoperation of a pair of hydraulic cylinders 260 and 262 which are fixedat one end to beam 274 (FIG. 20) located between rails 248 and to beam275 situated between the ends of rails 246 at their opposite end (FIGS.16 and 17). Rails 254 move in the opposite direction of rails 248 by asingle hydraulic cylinder 264 which is secured at one end to beam 280(FIG. 19) located between stationary rails 246 and at its opposite endto beam 276 (FIG. 18) positioned between rails 254. By incorporating twohydraulic cylinders 260 and 262 to advance saw support plate 24 and asingle hydraulic cylinder 264 to move counterbalance 146, counterbalance146 travels one-half the distance that saw support plate 24 travels,reducing the amount of space that power saw 10 requires.

[0048] Pivots 282 (FIG. 15) in the second embodiment are disposed oneither side of balancing apparatus 244 and extend to a point above rails246 and 248 of balancing apparatus 244. Pivots 282 include supports 284which are secured at one end to platform 14. At the opposite end ofsupports 284 are connecting plates 286 attached to supports 284 byfasteners 288. Disposed between connecting plates 286 on each side ofbalancing apparatus 244 is rod 290, the ends of which are rotatablysupported in connecting plates 286. Fixed to the lower portion of rod290 is cross beam 292 which extends the length of rod 290. Downwardlyextending from each end of beams 292 are connecting members 294,disposed substantially perpendicularly to beam 292 to link rod 290 andrails 246 of balancing apparatus 244. The opposite end of connectingmembers 294 are attached to rails 246 by fasteners 296.

[0049] Pivots 28 of the first embodiment are positioned at the lowersurface of balancing apparatus 26 which causes saw blade 46 to be forcedfurther into rail 20 as blade 46 is oscillated downwardly. By pivotingpower saw 10 from a point above balancing apparatus 244, saw blade 46 isdrawn backwards, away from rail 20 as it moves down into rail 20 ratherthan being forced forward into rail 20. In many situations, thisconfiguration provides saw 10 with a better angle of attack on rail 20which reduces stress of saw blade 46 and provides rail 20 with asmoother cut surface.

[0050] Pulley assembly 266 (FIGS. 16 and 17) of the second embodimentincludes linear chain 268 that is fixed at each end 270 and 272 to crossbeams 274 and 276, respectively. Chain 268 is engaged on pulley 278which is rotatably mounted to beam 280 secured to the outer edges ofstationary rails 246 (FIG. 19). As saw support plate 24 andcounterbalance 146 advance in opposite directions, the length of chain268 between pulley 278 and beam 276 lengthens, shortening the length ofchain 268 between pulley 278 and beam 274.

[0051] Even though not shown in the figures, covers are provided toprotect the inside of saw 10 underneath saw support plate 24 andbalancing apparatus 26 as well as covers for the upper portion of sawblade 46 and drive belt 48. Further, a hydraulic cylinder (not shown)may be arranged near end 238 (FIG. 1) of rail 20 to force end 238 awayfrom the rest of rail 20 as it is being cut. When the hydraulic cylinderis actuated, it would open up the cut, reducing pressure on saw blade46. Advancing power saw 10 is not limited to cutting steel railroadrails 20, it may be used to cut other metals such as stainless steel.Power saw 10 may also be adapted with coolant jets to reduce thetemperature of rail 20 during the cutting operation. Referring to FIG.14, a plurality of coolant jets 242 may be arranged on both sides of sawblade 46 at 45° and 90° angles to blade 46 to provide adequate coolantto reduce the temperature of rail 20.

[0052] In operation railroad rail 20 is brought a desired distance alongsupports 240 such that the point at which rail 20 is to be cut alignswith saw blade 46. Drive motor 44 starts rotating drive belt 48 and thusshaft 118 to begin rotation of saw blade 46. Oscillating motor 50 beginsto operate driving plate 60 back and forth in the direction of arrow 62causing connecting arm 54 and plate 78 to actuate in the direction ofarrow 80. This creates contact at point 112 which raises saw supportplate 24 and saw blade 46 begins the up and down motion of saw blade 46in the direction of arrow 42. When saw blade 46 is operating at theproper speed and is oscillating in a continuous motion, rod 186 ofhydraulic cylinder 184 begins to push saw support plate 24 towards rail20. Simultaneously, counterbalance 146 of balancing apparatus 26 beginsto move away from saw blade 46 so as to balance blade 46 and reducevibrations in saw 10 during the cutting operation (FIGS. 11-13). Oncesaw blade 46 is completely through rail 12 as shown in FIG. 13, rod 186of hydraulic cylinder 184 retracts bringing saw blade 46 and thebalancing apparatus 26 closer together towards the initial position(FIG. 11). Oscillating motor 50 is shut off as is drive motor 44 so thatadvancing power saw 10 returns to the initial position of FIG. 11.

[0053] In the exemplary embodiment of power saw 10, the overalldimensions of saw 10 are approximately 10 to 12 feet long and 4 to 6feet wide. The width of power saw 10 is dependant on the width ofbalancing apparatus 26, including pulley assembly 194, taken from a forklift truck. A 125 horsepower motor is used to rotate drive belt 48 andthus saw blade 46 at a speed appropriate to cut through rails 20.Oscillation motor 50 is shown in the Figures as a 3 horsepower motor.Springs 32 of the exemplary embodiment shown in FIG. 2 are used tofacilitate oscillations of saw blade 46 and are the springs used asshock absorbers in a truck. Pivot supports 28 are positioned at one endof platform 14 to support balancing apparatus 26 at a pointapproximately one-third the distance of balancing apparatus 26 from end148. The opposite end of balancing apparatus 26 is supported byoscillating mechanism 30 which in relation to saw blade 46 isapproximately one-third the distance of saw support plate 24 from theend of plate 24. Counterbalance 146 supported at end 148 of balancingapparatus 26 is in a range between 400 and 1500 pounds which isdependant on the amount of vibrations produced during the cuttingoperation. The counterbalance moves about ½ the amount of thecorresponding movement of the saw blade in the exemplary embodiment.

[0054] While this invention has been described as having an exemplarydesign, the present invention may be further modified within the spiritand scope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

What is claimed is:
 1. An advancing power saw for cutting metal objects,said saw comprising: a platform; a support plate movably disposed onsaid platform; a saw blade assembly disposed upon said support plate,said saw blade assembly including a saw blade coupled with a motor andassociated with an oscillating mechanism; and a counterweightoperatively associated with said support plate and arranged to move in adirection opposite to the direction said support plate moves.
 2. Thepower saw of claim 1 further comprising an advancing mechanism, saidadvancing mechanism advancing and retracting said support plate.
 3. Thepower saw of claim 1 further comprising a plurality of rails, at leastone of said plurality of rails operatively connected to said supportplate, and at least one of said plurality of rails operatively connectedto said counterweight, whereby said rails are adapted to actuate inopposite directions.
 4. The power saw of claim 3 wherein counterweighthas a sufficient mass in relation to said power saw to dampen vibrationsin said power saw.
 5. The power saw of claim 3 wherein counterweight hasa sufficient mass in relation to said power saw to substantiallyequalize pressure on said saw blade.
 6. The power saw of claim 3 furthercomprising at least one hydraulic cylinder associated with said rails.7. The power saw of claim 3 further comprising at least one hydrauliccylinder associated with said counterweight and at least one hydrauliccylinder associated with said support plate.
 8. The power saw of claim 1wherein said oscillating mechanism further comprises an oscillatingmotor, said oscillating motor operatively associated with saidoscillating mechanism by a connecting arm.
 9. The power saw of claim 1further comprising at least one pivot support disposed at one end ofsaid platform.
 10. The power saw of claim 1 wherein said saw supportplate and said counterweight pivot about said pivot support.
 11. Thepower saw of claim 9 wherein said pivot support is disposed beneath saidrails.
 12. The power saw of claim 9 wherein said pivot support extendsabove said rails.
 13. The power saw of claim 1 further comprising apulley assembly, said pulley assembly coupled to said counterweight andsaid support plate, whereby said pulley assembly advances saidcounterweight in a direction opposite of said support plate.
 14. Anadvancing power saw for cutting metal objects, said saw comprising: aplatform having a movable support plate; oscillating saw means forcutting said metal objects disposed on said support plate; and balancingmeans for dampening vibration of said oscillation saw means.
 15. Thepower saw of claim 14 wherein said oscillating saw means includes a sawblade, said saw blade rotatably supported atop said support plate. 16.The power said of claim 14 further comprising at least one pivot supportwherein said saw support plate is supported above said platform by saidpivot support.
 17. The power saw of claim 16 wherein said pivot supportis disposed beneath said rails.
 18. The power saw of claim 16 whereinsaid pivot support extends above said rails.
 19. The power saw of claim14 wherein said oscillating saw means is operatively associated with anoscillating motor, said oscillating saw means and said oscillating motorcoupled by a connecting arm.
 20. The power saw of claim 14 wherein saidoscillating saw means further comprises an advancing mechanism, saidadvancing mechanism operatively associated with said support plate,whereby said advancing mechanism advances and retracts said saw blade.21. The power saw of claim 14 wherein said balancing means isoperatively associated with said support plate and arranged to move in adirection opposite to the direction said support plate moves.
 22. Thepower saw of claim 14 wherein said balancing means further comprises aplurality of rails, at least one of said plurality of rails operativelyconnected to said saw support plate, and at least one of said pluralityof rails operatively connected to said balancing means, whereby saidrails are adapted to actuate in opposite directions.
 23. The power sawof claim 22 further comprising at least one hydraulic cylinderassociated with said rails.
 24. The power saw of claim 22 furthercomprising at least one hydraulic cylinder associated with saidcounterweight and at least one hydraulic cylinder associated with saidsupport plate.
 25. The power saw of claim 14 wherein said balancingmeans supports at one end a counterbalance, whereby said counterbalancedampens vibrations in said power saw.
 26. The power saw of claim 25wherein said counterbalance is a weight related to the vibrations insaid power saw.
 27. The power saw of claim 25 wherein saidcounterbalance substantially equalizes pressure on said saw blade. 28.The power saw of claim 14 wherein said oscillating saw means furthercomprises a pulley assembly, said pulley assembly coupled to saidbalancing means and to said support plate, whereby said pulley assemblyadvances said balancing means in a direction opposite of said supportplate.